In manufacturing corrugated board containers, sheets of corrugated board (blanks) are fed into a die cutting apparatus which typically trims, creases and cuts the corrugated board blank to form a corrugated board product that typically assumes a sheet form but which can be readily folded and shaped into a corrugated board container. Various types of die cutting assemblies are conventionally used. Basically, however, there are two types of die cutting assemblies--a rotary die type and a flat die type. In either case, the die assembly includes a die board. The die board is designed to perform a variety of functions on the corrugated board blanks. Typically, the die board is provided with cutting blades, scoring rules, and rubber scrap and product ejectors.
Cutting blades and scoring rules, which are collectively referred to herein as blades, are typically permanently or at least semi-permanently mounted in the die board. This, of course, means that they are not easily removed from the die board. Generally, in manufacturing die boards, a slit or groove is cut within the die board to conform with a blade or knife pattern design. The width of the slit or groove is specifically cut such that a strong frictional fit is achieved after the blade is pressed into the slit. In any event, the fit is sufficiently tight that the blade remains stationary or stable even through repeated and long die cutting operations.
For the most part, blades are not generally removed from die boards. If they are removed, the task becomes tedious, time-consuming and in the end very difficult and even costly. Because of this, blade adjustment or replacement is not routine. Most corrugated container manufacturers, when faced with blade replacement, will ship the cutting die back to the die maker for blade replacement.
However, there has been and continues to be a need for a die board that enables operators to quickly and easily exchange blades or adjust the position of existing blades within the die board. For example, one situation that comes to mind deals with the problem of forming nicks in blades. Nicks are small indentions made in the tip of blades for the express purpose of preventing the blade in the area of the nick from making a complete cut through the corrugated board blank. Thus, by appropriately nicking a blade, the operator can provide a very thin attachment between two adjacent corrugated panels, for example. This is a common practice in the corrugated board industry as nicks are widely used in certain situations to maintain a very thin and easily breakable connection between two panels of corrugated board.
Nick blades are provided in a variety of ways. Unfortunately, and all too often, die operators form nicks on existing blades with tools, such as a screw driver and hammer, while the blade is held within the die board. Such nicks are far from precise and the corrugated board product cut by such nick blades will reflect such. Moreover, once formed, these nicks are difficult to adjust, if adjustment can be made at all. From time to time, because of the nature of these die cutting assemblies, adjustments will have to be made. To replace or make such adjustments die operators may attempt to remove the nick blade or blades from the die board. But as pointed out above, this is a time-consuming and expensive procedure because to do so requires that the die cutting apparatus be shut down. Furthermore, the average die operator does not necessarily possess the skill or the training to efficiently remove and reinsert blades of any type within the die board.